Three-axis, adjustable loading structure

ABSTRACT

A three-axis, adjustable loading structure is provided for test equipment wherein it is desired to exert pressure against the structure which is to be tested. The device of the present invention is provided with three electric drives whereby the wall angle, horizontal position, and vertical position of the test device can be rapidly and accurately positioned. The invention described herein was made by employees of the United States Government and may be manufactured and used by or for the Government for Governmental purposes without the payment of any royalties thereon or therefor.

United States Patent 11 1 Lynch et al.

[451 Dec. 4, 1973 THREE-AXIS, ADJUSTABLE LOADING STRUCTURE [22] Filed:May 16, 1972 [21] App]. No.: 253,725

FOREIGN PATENTS OR APPLICATIONS 137,695 10/1960 U.S.S.R 73/88 R PrimaryExaminer-Jerry Wv Myracle Attorney-Darrell G. Brekke et al.

[57] ABSTRACT A three-axis, adjustable loading structure is provided fortest equipment wherein it is desired to exert pressure against thestructure which is to be tested. The device of the present invention isprovided with three electric drives whereby the wall angle, horizontalposition, and vertical position of the test device can be {.Lf. (g1.73/88 R;;%)l4/9330R0 rapidly and accurately positioned /88 3 Theinvention described herein was made by 79 employees of the United StatesGovernment and may be manufactured and used by or for the Government[56] References Cited for Governmental purposes without the payment ofany royalties thereon or therefor. UNITED STATES PATENTS I 2,096,9641937 Frocht 713/88 R 4 Claims, 6 Drawing Figures m 22 67 /Pe 5e 24 m 4\i 57 55- 83 8 9| ,2 25 o 45 4g 33 43 Q t o \I ll 7 I Z9 2 3 23 oo 9 D QD 0 I?) Q 17 PAIENTED mm 4 1915 SHEEY 2 BF 4 PATENTEU DEC 4 I975 SHEETU, U? 4 .ITILiF -5- THREE-AXIS, ADJUSTABLE LOADING STRUCTURE BACKGROUNDOF THE INVENTION SUMMARY OF THE INVENTION In testing structures, such asthe movable surfaces of flight vehicles, it is necessary to impose loadson the surface and it is important that the load be applied normal tothe surface. Since such tests are frequently conducted at variousattitudes of the surface to be tested, it was previously necessary toprovide a large number of fixtures, or to modify existing fixtures, sothat in effect, one had to provide a separate fixture for each increment to be tested. This involved a number of drilling and cuttingoperations, since the test instrument had to be adjusted vertically andhorizontally to maintain a perpendicular attitude to the surface. Thisalso involved changing the angle of the vertical axis of the base thatsupported the test instrument.

In the past to make such cnanges in the test fixture, it required hoursor even days to go from one test posia three-axis loading device whereinthe wall angle, the horizontal position, and the vertical position areall adjustable by means of electric motors. Thus, instead of spendingmany hours or days in going from one testposition to another, one canachieve these changes in a matter of minutes. Furthermore, the device ofthe present invention permits more precise adjustment so that theresults of the tests are more accurate. The .device of the presentinvention has been estimated to saveSO to 90 percent in the set up timeof goingfrom one test position to another. The device of the presentinvention is simple to construct and is ruggedly built and littlemaintenance is required.

BRIEF DESCRIPTION OF DRAWINGS of FIG. 2.

FIG. 5 is a plan view on the line 5-5 of FIG. 2. FIG. 6 is a section onthe line 6-6 of FIG. 2.

DESCRIPTION OFTHE PREFERRED EMBODIMENTS The device of the presentinvention includes a rectangular frame member generally designated 7,having front and back rails 9 and 11, andtwo side rails designated 13.Frame 7 can be bolted to a floor or other supporting structure or it canbe fastened to a sub frame tion to another. The device of the presentinvention is i section, generally designated 15, to elevate it to a suitable height. The subframe may be mounted for rotation.

Two hinge members 17 and 19 are mounted on the front rail 9 and the wallmember generally designated 21 is pivotally mounted on these hingemembers. Wall member 21 includes a top rail 22, a bottom rail 23 andside rails 24. r

In order to support wall member 21 at a desired angle and to change theangle at will, the threaded struts 25 and 27 are employed. These aremounted on frame 7 by means of the support member 29 and 31 on which aremounted the angle drive members 33 and 35 which, through the use ofbevel gears, as at 36, are adapted to rotate struts 25 and 27. Struts 25and 27 pass through threaded collars 37 and 39 respectively which areattached by means of yolks 41 to the side members 24. Yolks 41 are freeto pivot on the frame 21 and also pivotally mounted with respect to thethreaded collars 37. and 39. The angle drives 33 and' 35 are also freeto pivot on their respective mountings. Motor 43 is connected to gearbox 45 and this drives shaft 47 which actuates angle drive 33 and angledrive 35. Thus, by running motor 43 in one direction or the other, thewall angle can be changed at will through the rotation of the threadedstruts 25 and 27.

The test fixture proper is mounted on a cross beam,

, generally designated 49, which is later described in detail. Beam 49is mounted for vertical movement on the threaded struts 51 and 53, eachof which terminates in threaded collars 55 and 57 attached to thehorizontal beam 49. Struts 51 and 53 are connected by means of angledrives 59 and 61 to the vertical traverse motor 63. Beam 49 slides upand down on the side members i cal traverse of the beam 49.

The horizontal beam 49 carries the jack pad support box 69 and this ismounted on an upper rail 71 and a lower rail 73, both of which are madeof square bar stock and which are mounted with their flat surfaces at 45to the surfaces of the horizontal beam by means of hangers 75. The jackpad is mounted (see FIG. 3) on the lower rail 73 by means of pairedroller bearings, namely, front bearings 77 and rear bearings 79.However,the top of the jack pad support box. is mounted on single rollerbearings 81 which bear against only the rear surface of upper rail 71.The reason for this will be later explained.

To secure horizontal traverse of the jack pad support box, a threadedrod 83 passes through the box and is.

rotated by means of a motor 85. A threaded collar 87 is pivotallymounted on the box 69 so that by rotating the motor in one direction orthe other,the box 69 is cause to traverse horizontally.

The load ram 89 is fastened directly to thebox 69 and is provided withsuitable hydraulic connections as at91 and 93. The load cell 95.isconnected to the end of the ram and is provided with suitableelectrical con nections as at 97.

It was previously mentioned that the jack padsupport box 69 had only asingle pair of bearingsat the top .and that these bear against the rearsurface of rail 7 1. The

reason for this can best be seen in FIG. 3. Before a test is made, theweight of the ram 89 and the test cell 95 will cause the jack pad box totend to rotate in a clockwise direction so that the box will rest on thebottom bearings 77 and 79 and on the top bearing 81. However, when aload is applied to the device when it is in position, the jack pad box69 will be forced backwards into direct contact with the horizontal beam49 which in turn will be forced into contact with the uprights 24. Thus,when the device is being used for a test, there is no load on thebearings, since the bearing 81 will be forced back from the rail 71, andthe load will be applied directly against the support members 49 and 27.

An electric control box 99 is employed for actuating motor 43 to controlthe wall angle, motor 63 to control the vertical traverse and motor 85to control the horic. adjustment means whereby said wall member can bepivoted and held in a given position,

d. a horizontal beam mounted for vertical movement on said wall member,

' e. means for moving said beam vertically to a desired position,

f. a jack pad support member mounted on said beam for horizontalmovement and means for moving said jack pad support member horizontallyalong said beam, and

g. a jack mounted on said jack pad support member.

2. The structure of claim 1 wherein a first pair of threaded struts isused to support said wall member and having motor means to drive saidthreaded struts.

3. The structure of claim 1 wherein said beam is mounted on said wallmember by means of threaded rods and having motor means whereby saidbeam threaded rods are rotated to drive said in an up and downdirection.

4. The structure of claim 1 wherein the jack pad support member ismounted between upper and lower rails carried by said horizontal beam,said jack pad having pairs of lower bearings in contact with both frontand back surfaces of said lower rail and single upper bearings incontact with only the rear surface of the upper rail whereby a forceapplied to the jack pad will not be applied to said rails but said jackpad will be forced directly against said horizontal beam.

1. A three-axis adjustable loading structure comprising in combination:a. a base frame member, b. a wall member mounted for pivotal motion onone edge of said frame member, c. adjustment means whereby said wallmember can be pivoted and held in a given position, d. a horizontal beammounted for vertical movement on said wall member, e. means for movingsaid beam vertically to a desired position, f. a jack pad support membermounted on said beam for horizontal movement and means for moving saidjack pad support member horizontally along said beam, and g. a jackmounted on said jack pad support member.
 2. The structure of claim 1wherein a first pair of threaded struts is used to support said wallmember and having motor means to drive said threaded struts.
 3. Thestructure of claim 1 wherein said beam is mounted on said wall member bymeans of threaded rods and having motor means whereby said beam threadedrods are rotated to drive said in an up and down direction.
 4. Thestructure of claim 1 wherein the jack pad support member is mountedbetween upper and lower rails carried by said horizontal beam, said jackpad having pairs of lower bearings in contact with both front and backsurfaces of said lower rail and single upper bearings in contact withonly the rear surface of the upper rail whereby a force applied to thejack pad will not be applied to said rails but said jack pad will beforced directly against said horizontal beam.